The Siemens 3UG4616-1CR20 is a SIRIUS network monitoring relay with digital setting, designed to monitor three-phase AC mains for phase loss, phase sequence, asymmetry, and overvoltage. It covers a rated voltage range of 90 to 400 V at both 50 and 60 Hz, making it suitable for global 400 V class distribution panels. The relay switches loads up to 3 A at 250/400 VAC, enough to signal a PLC input or drop out a contactor coil directly.
The 90–400 VAC sensing range means this relay works on 208, 240, 380, and 400 V systems without a separate PT — one part covers most low-voltage industrial supplies. Asymmetry detection catches a blown fuse or single-phasing motor condition before the load overheats. The LCD display shows the actual line voltage and fault codes, which speeds troubleshooting on a live panel compared to a simple LED bar.
The 22.5 mm width takes one standard module slot, leaving room for a contactor and overload next to it. Screw terminals accept 2 x (20–14) AWG solid or stranded, typical for control wiring.